Adapter housing for door locks



Nov. 20, 1956 Filed Oct. 19, 1953 Ryz L. c. BIGELOW ADAPTER HOUSING FORDOOR LOCKS 3 SheetsSheet 1 INVENTOR. A r/ww 6. 3/854 0 w ham W;

Nov. 20, 1956 BIGELOW ADAPTER HOUSING FOR DOOR LOCKS 3 Sheets-Sheet 2Filed Oct. 19, 1955 WEE-HIP INVENTOR. L YPO/FD C. 5mm. 0 w

' Nov. 20, 1956 Filed Oct. 19, 1953 L. c. BIGELOW 2,770,964

ADAPTER HOUSINGFOR DOOR LOCKS 3 SheetS- -Sheet 3 42 INVENTOR.

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United States Patent() ADAPTER HOUSING FOR DOOR LOCKS Lyford C. Bigelow,New Britain, Conn., assignor to The American Hardware Corporation, NewBritain, Conn., a corporation of Connecticut Application October 19,1953, Serial No. 386,956

20 Claims. (Cl. 70-451) This invention relates to an adapter housing fordoor locks and more particularly to a housing for supporting acylindrical door lock on a thin door to which the lock could not benormally applied by conventional means.

As is well known to those skilled in the art, door locks of thecylindrical type generally include a latch operating unit and a separatelatch unit. The operating unit usually includes a cylindrical case whichis normally received in a hole extending through the face of the doorand is provided at its inner and outer sides with co-axial sleeves whichcarry the rotatable knob shanks that operate the retractor mechanismcontained in said case. Said sleeves also receive the escutcheon plateswhich are normally employed to secure and support the operating unit onthe door. The latch unit is received in a hole extending through theedge of the door and is secured to the operating unit by suitable means;the latch bolt in said latch unit being operated by the retractormechanism in the case of the operating unit.

It will be understood that the width of the case of the operating unitdetermines the minimum distance obtainable between the inner and theouter escutcheon plates, when moved to their innermost positionsrelatively to the case, and thereby limits the minimum thickness of adoor to which the lock may be applied; such minimum thickness usuallybeing in the neighborhood of 1% inches.

Modern buildings being erected at the present time are often providedwith doors considerably thinner than those upon which cylindrical doorlocks may generally be applied and this is particularly true with theexterior doors thereof which are often constructed of glass. Such doorsgenerally range in thickness from A to 1 inch, thereby rendering itimpossible to mount a conventional cylindrical door lock thereon withthe escutcheon plates tha are commonly provided.

The primary object of this invention, therefore, is to provide anadapter housing which will permit the use of conventional cylindricaldoor locks on relatively thin doors.

A further object of this invention is to provide an adapter housingwhich contains and supports a cylindrical latch operating unit and alatch unit and is applicable to thin doors; particularly those made ofglass, and which is provided with means for concealing the parts of thecylindrical door lock.

A still further Object of the present invention is to provide such ahousing incorporating novel fastening means for securing it to the door.

Another object of the present invention is to provide a housing forsupporting a cylindrical latch Operating unit, a backset extension, anda latch unit in a glass door.

Another object is to provide such a housing having novel means forsecuring the latch unit of the door lock therein; said means also actingto secure the housing to the door. Further objects and advantages ofthis invention will be more clearly understood from the followingdescription and the accompanying drawings in which:

Fig. l is a plan view illustrating the housing embodyle Patented Nov.20, 1956 ing the present invention and the cylindrical door lock carriedthereby in position on a thin glass door.

Fig. 2 is an end view thereof as it would appear when viewed from theedge of the door.

Fig. 3 is a view illustrating the appearance of the housing and thecylindrical door lock when viewed from the inner side of the door. 6

Fig. 4 is an enlarged plan view of the housing, in central horizontalsection, illustrating the relative positions of the main parts of thehousing when applied to a door.

Fig. 5 is asectional end view of the housing, on a reduced scale, takenon line 55 of Fig. 4.

Fig. 6 is a similar View taken on line 66 of Fig. 4.

Fig. 7 is a similar view, taken on line 77 of Fig. 4.

Fig. 8 is a side View illustrating the face of the outer plate of thehousing.

Fig. 9 is a similar view illustrating the face of the inner plate of thehousing.

Fig. 10 is an end view of the inner and the outer plates of the housingin disassembled position.

Fig. 11 is an enlarged plan view of the housing, partially in centralhorizontal section, illustrating a cylindrical door lock therein and themanner in which said lock is secured to a door by said'housing.

Fig. 12 is a view similar to Fig. 11, but illustrating only the outerend of the housing and having portions of the latch unit broken away toillustrate the means which both secure the latch unit to the housing andclamp the inner and outer plates of the housing to the door.

Fig. 13 is a side view, taken in section substantially on line 13-13 ofFig. 11, further illustrating the housing as applied to a door.

Fig. 14 is an end view thereof, taken in section on line 1414 of Fig. 11, to further illustrate the manner in which the cylindrical latchoperating unit is secured in the housing.

The adapter housing disclosed herein is particularly intended for usewith the cylindrical door lock incorporating the operating unit whosebasic construction is illustrated in United States Patent No. 2,701,160,dated February 1, 1955, and for the purpose of illustration, the saidunit will be briefly described.

The cylindrical door lock includes a latch operating unit, generallyindicated at 5, and a latch unit, generally indicated by the numeral 6.In the instant disclosure, a conventional backset extension 7 is alsoprovided to connect the latch operating unit to the latch unit. Saidlatch operating unit includes a cylindrical case 8 which contains aretractor mechanism, such as that illustrated in United States PatentNo. 2,721,095, dated October 18, 1955, and is provided with an innersleeve 9 and an outer sleeve 10 which are co-axially disposed androtatably support the knob shanks which are secured to the inner andouter .door knobs 11 and 12, respectively, in the manner illustrated inUnited States Patent No. 2,675,692, dated April 20, 1954. The inner knobshank is retained in the sleeve 9 by a retaining member 13 and the outerknob shank is retained in the sleeve 10 by a retaining member 14 whichis secured in retaining position by screws extending through the case inthe manner clearly illustrated in the above mentioned Patent No.2,701,160. Each of said sleeves 9 and 10 is provided with a threadedportion 15 and 16, respectively, which normally receives an escutcheonplate that is employed to clamp'the latch operating unit to a door. Theoperating unit illustrated in the accompanying drawing is provided witha locking mechanism that is actuated by a turnpiece 17 in the inner knob11 for dogging the outer knob against rotation; said outer knob beingprovided with key-operated means, not shown, to permit operation of thelatch bolt when the .outer knob is dogged against operation.

' The latch unit 6 is also of conventional form and includes a tubularcase 18 having a face plate 19 secured thereto through which extends amain latch bolt 20 and an auxiliary latch bolt 21. The face plate isprovided with the conventional holes therethrough to receive the screwsnormally used for securing :the latch unit in the hole in the edge ofthe door. Said main latch bolt 20 hasa tail 22 extending therefromthrough the bottom of the case 18 which is adapted to be secured to theretractor in the operating unit. In the instant disclosure, however, abackset extension 7 is employed between the latch unit and the latchoperating unit, and, as bestillustrated in Figs. ll and 13, said backsetextension is secured at one end to the latch unit and at its oppositeend to the latch operating unit through the engagement of cars 23-23thereon with the edges of the notch 24 in the case of the operatingunit. Said backset extension is provided with a movable retractor link25 which is secured at one end to the retractor of the operating unitand at its opposite end to the tail 22 of the latch bolt as clearlyshown in Fig. 13. The door lock above described forms no part of thepresent invention, but was included in the disclosure to exemplify theuse of the housing.

The adapter housing embodying the present invention includes an outerplate 26 and an inner plate 27. The outer plate 26, as best illustratedin Fig. 8, includes a circular end portion 26-n and a radially extendingstraight sided portion 26b. The inner face of the plate is flat and isprovided with a recess 28 defining a flange 29 along its marginal edges.Said plate also has a perpendicularly extending wall 30 thereon having acircular portion 31 disposed eo-axially of the circular portion 26-a ofthe plate and spaced horizontally extending side walls 32-32; theintermediate portions 32-a-32-a of said side walls being spaced adistance less than the diameter of the circular portion 31. The outerend of the .plate is formed to provide .a perpendicularly extendingframe 33 which projects beyond the edges of the wall 30 and has anopening 34 therethrough. A pair of pins 35-35 are disposed across theopening 34 adjacent its upper and lower ends for a purpose to behereinafter described.

The outer surface of the plate 26 contains a circular boss 36surrounding a hole 37 therein which is disposed co-axially of thecircular portion 31 of the wall 30 and is preferably surrounded by arecess 38 in the inner surfa'ceof the plate.

Projecting from said inner surface are a'pad 39, aboss 40 havingperpendicularly extending guide fingers 41-41,

and a pair of bosses 42-42 which are formed adjacent the opening 34 inthe frame at the intersection of the side walls 32-32 with the innersurface of the plate and each of said bosses contains a recess 42-1:with a tapered vertical side wall 42b forming a cam surface.

The hole 37 in the outer plate may be internally threaded, but ispreferably adapted to receive an internally threaded bushing 43 which isnon-rotatably secured in said hole by being brazed, or otherwisepermanently secured, to the plate as illustrated at 44.

The inner plate 27 has an exterior configuration identical to that ofthe outer plate and the surface thereof which faces the door is providedwith a recess, as at45, defining a flange around its marginal edge. Thesaid plate is provided with a hole 46 therethrough which is disposedco-axially of thecircular portion 47 of the plate and from the marginaledge portions of which extends a perpendicular wall 48 having anexternal diameter substantially equal to the internal diameter of thecircular portion 31 of the wall on the outer plate 26. Said wall 48terminates adjacent a pair of lugs 49-49 which extend perpendicularlyfrom the inner surface of the plate 27 and are adapted to enter thenotch 24 in the case of the latch operating unit for a purpose to behereinafter described. Said plate 27 is provided with a pad 50 and aboss 51 having fingers 52-52 extending perpendicur 4 larly therefrom;said elements being disposed opposite the elements 39 and 40 of theouter plate.

A pair of bosses 53-53 extend from the inner surface of the plate 27 andare each provided with a recess 53-5: having a tapered vertical sidewall 53-h forming a cam surface therein in the same manner as in therecesses of the bosses 42-42 above described. The outer end of theplate. 27 contains a notch 54 which is adapted to receive the frame onthe outer plate 26 as clearly illustrated in Figs. 2 and 3.

In the accompanying drawings, I have illustrated my adapter housing asapplied to a thin glass door and it will be noted from Fig. 13 that saiddoor, indicated at 55, is provided with a hole 56 which extends inwardlyfrom its free edge and conforms to the exterior shape of the .center ofthe case 8 of said unit is in a position wherein it will lie on avertical plane extending through the center of the door. The outer knobshank is then replaced and secured in position by the retainer 14 whichis accessible through the space between the side of the case 8 and thebottom of the recess 38. The latch unit 6 is then inserted through theopening 34 in the frame on the outer plate until the face plate 19thereon is disposed within said opening and its inner surface is inengagement with the pins 35-35 extending thereacross. Suitable screws57- 57 arethen inserted through the holes provided in the face plate andare threaded into horizontally disposed U- shaped clamping bars 58-58having legs 59-59 with tapered inner cam surfaces 60-60. Said screws57-57 are, at this point, merely started into the threaded holes in theclamping bars 58-58 so that the ends of the legs 59-59 of said bars willbe disposed inwardly of their respective bosses 42 and 53. The faceplate is manually urged against the pins 35-35 to retain the latch unitin proper position to receive the backset extension 7 which is theninserted into proper position between the latch unit and the operatingunit and is secured thereto in the conventional manner as clearlyillustrated in Figs. 11 and 13.

The inner knob 11 and its shank are then removed from the inner sleeve 9by releasing the inner knob shank retainer13. The outer plate, whichthen carries the operating unit, the backsetextension and the latch unitis positioned against the outer surface of the door 55 by inserting thewall 30 into the opening 56 in said door.

The inner plate 27 is then passed over the inner sleeve 9 and the wall48 thereonpassed over the case 8 of the operating unit and inserted intothe circular portion 31 of the wall 30 on the outer plate. At the sametime, the notch 54 in the outer end of said plate will receive the frame33 on the outer end of the outer plate 26 and the bosses 53-53 on saidinner plate will enter between the side walls 32-32 of the wall on saidouter plate to properly locate the outer end of the plate 27 relativelyto the outer plate 26. The said inner plate is moved into engagementwith the door and an escutcheon plate 61 is placed over the inner sleeve9 and against the outer surface of the inner plate as illustrated inFig. 11. Said escutcheon plate 61 has a configuration identical to theboss'36 on the outer plate and is provided with a centrally disposedopening '62 which rotatably receives a bushing 63 similar to the bushing43. Said bushing 63 is threaded to the threaded portion 15 of the innersleeve 9 and is'adapt'e'dto clamp the escutch'eon plate 61 against theinner plate 27 whereby saidinner plate is clamped securely against theinner surface of the door and the outer plate is drawn securely againstthe outer surface S of the door through the tension applied through thelatch operating unit.

In order to secure the latch unit in the housing and to securely clampthe inner and outer plates against the door at their outer ends, thescrews 5757 are rotated thereby causing the tapered surfaces 60-60 onthe legs of the clamping bars 58 to move into engagement with thetapered surfaces 42b and 53b on their respective bosses 42 and 53. Itwill be understood that by tightening the screws 5757, the face plate ofthe latch unit is urged securely against the pins 3535 and, at the sametime, the inner and outer plates are cammed tightly against the surfacesof the door.

After the housing has been assembled to the door as above described, theinner knob 11 and its shank are assembled to the latch operating unit tothereby complete the installation.

If desired, suitable inserts 6464 of a plastic or other soft materialmay be placed between the plates 26 and 27 and the surface of the doorto avoid a metal to glass contact.

It will be noted, particularly from Fig. 11, that the pads 39 and 50 onthe outer plate 26 and the inner plate 27, respectively, serve to retainthe backset extension cen trally of the housing and that the bosses 40and 51 locate the latch unit and the backset extension in a similarposition. The fingers 4141 and 52-52 on said bosses 40 and 51 preventvertical movement of the latch unit and the backset extension to therebyretain them in proper alignment. It will be further noted, particularlyfrom Figs. 11 and 13, that the lugs 49-49 on the inner plate 27 projectinto and engage the sides of the notch 24 in the case of the operatingunit to prevent rotation of said unit should an undue torque be appliedto either of the knobs 11 or 12.

The circular portion 31 of the wall on the outer plate 26 preventswithdrawal of the housing from the edge of the door through theengagement thereof with the sides of the opening 56 in the door 55 tothereby provide the required degree of security. The wall 30 and thewall 48 telescopicallyreceived by the portion 31 thereof also concealthe parts of the door. look from view when the unit is used on a glassdoor thereby enhancing the appearance of the installation.

It will thus be seen that the present invention provides a housing forsupporting a cylindrical door look upon a thin glass door which isattractive in appearance, durable in construction and simple to install.

I claim:

1. For a cylindrical door lock including a latch operating unit and alatch unit, said operating unit including a case having sleevesextending co-axially from the opposite sides thereof; an adapter housingfor mounting said door lock on a door that is thinner than the saidcase, the said adapter housing including an inner and an outer platewhich are adapted to be disposed at the opposite sides of the door andeach of which contains a recess in its face to provide a space betweenthe plates which is greater than the thickness of the door toaccommodate the casing of the operating unit, means on said plates forpositioning the latch unit therebetween in operative relation with themechanism contained within said case, means on the outer platecooperating with said outer sleeve for securing the plate thereto, andmeans cooperating with the inner sleeve for urging the inner plateagainst the door to thereby draw the outer plate into clamping positionthrough tension applied to the operating unit.

2. For a cylindrical door lock including a latch operating unit and alatch unit having a face plate, said operating unit including a casehaving an inner and an outer sleeve extending co-axially therefrom; anadapter housing for mounting said door lock on a door that is thinnerthan said case, the said adapter housing including an inner and an outerplate which are adapted to be disposed at opposite sides of the door andeach of which contains a recess in its face providing a space betweenthe plates which is greater than the thickness of the door toaccommodate the case of the operating unit, means cooperating with saidsleeves for supporting said operating unit with the case thereof betweensaid plates and for urging the the cam means on said plates, and meansfor urging said cam means on the clamping bar into engagement with thecam means on said plates for drawing the plates against the oppositesides of the door.

4. The subject matter set forth in claim 2 wherein said separate meansincludes cam means on each of said plates, a clamping bar having cammeans thereon engageable with the cam means on said plates, abutmentmeans on at least one of said plates engageable by a. portion of thelatch unit, and a screw member projecting through a hole in the faceplate of the latch unit and threaded to said clamping bar for drawingthe cam means thereon into engagement with the cam means on said plate,

5. For a cylindrical door lock including an operating unit and a latchunit, said operating unit having a case within an inner and an outersleeve extending co-axially therefrom; an adapter housing for mountingsaid door lock on a door that is thinner than said case, the saidadapter housing including an inner and an outer plate each of whichcontains a recess in its face defining a flange therearound adapted toabut the surface of the door, a wall extending perpendicularly from thebottom of the recess in the outer plate, a wall extendingperpendicularly from the bottom of the recess in the inner plate andfitting telescopically a portion of the wall on the outer plate toprovide a closed chamber for containing the case of the operating unit,means on said outer plate for securing it to the said outer sleeve,means connected to the inner sleeve for urging the inner plate againstthe door whereby the outer plate is urged against the door through thetension applied through the operating unit, and means on said plates forsecuring the latch unit therebetween in operative position relatively tothe mechanism in the case of the operating unit.

6. The subject matter set forth in claim 5 including separate meansbetween said plates, accessible only when the door with the said adapterhousing thereon is in open position, for drawing the said platestogether into clamping position against the portions of the oppositefaces of the door near the edge thereof.

7. For a cylindrical door lock including an operating unit and a latchunit, the said operating unit including a case; an adapter housing formounting said door lock on a door that is thinner than the case, saidadapter housing including an inner and an outer plate each of whichcontains a recess in its face to provide a space between said plateswhich is greater than the thickness of the door and is adapted toaccommodate the case of the operating unit, means cooperating with saidoperating unit for securing it to said housing with the case thereofbetween said plates and for urging the inner ends of said plates againstthe opposite sides of the door, and separate means securing the latchunit to the said housing and drawing the outer portions of said platestoward each. other to clamp them to the door.

8. For a cylindrical door lock including an operating;

unit and a latch unit, the said operating unit including; a case havingan inner and an outer sleeve extending c0-- than the case, said housingincluding an inner and an outer plate each of which. contains a recessin its face toprovide'a space between said plates that is adaptedto-accornmodate the case of the operating unit, the said plateshaving-co-axial openings extending therethrough adjacent their innerends to receive said sleeves, means cooperating with said sleeves forsecuring said operating unit in position within said housing and forclamping the inner ends of the plates to the door, and separate meanssecuring the latch unit to said housing and clamping the outer ends ofthe plates to the door.

9. Fora cylindrical door lock including an operating unit and a latchunit, the said operating unit including a case having an inner and anouter sleeve extending coaxially therefrom; an adapter housing formounting said door lock on a door that is thinner than the case, saidadapter housing including an inner and an outer plate having coaxialopenings therein to receive said sleeves and each plate containing arecess in its face providing a space between said plates which isgreater than the thickness of the door and is adapted to accommodate thecase of the operating unit, means between said outer plate and the outersleeve securing the operating unit to the outer plate, means on each ofsaid plates coaxial with said openings for aligning the plates andcontaining the case of the operating unit, means for securing the latchunit between said plates and in operative position relatively to theoperating mechanism in said case, and means cooperating with a threadedportion on the inner sleeve for urging the inner plate against the doorto thereby force both of said plates securely against the opposite sidesof the door through tension applied to the operating unit.

10. For a cylindrical door lock including an operating unit and a latchunit, the said operating unit including a case; an adapter housing formounting said door lock. on a door that is thinner than the case and isprovided with an opening therein to receive said case, said adapterhousing including an inner and an outer plate each of which contains arecess in its face providing a space between said plates which isgreater than the thickness of the door and is adapted to accommodate thecase, means for securing the case to said housing and clamping theplates against the opposite sides of the door, separate means forsecuring the latch unit to the housing and clamping said plates to theopposite sides of the door, and a wall extending perpendicularly from atleast one of said plates and conforming with the shape of the opening insaid door for preventing displacement of the housing relatively thereto.

11. The subject matter set forth in claim wherein thewall has anenlarged portion fitting within a correspondingly formed portion of theopening in the door to prevent movement of the housing relativelythereto.

12. The subject matter set forth in claim 10 wherein said wall overliesthe marginal edge portions of the open ing in the door.

13. For a cylindrical door lock including an operating unit and a latchunit, the said operating unit including a case; an adapter housing formounting said door lock on a door that is thinner than the case, saidadapter housing including an inner and an outer plate each of whichcontains a recess in its face to provide a space between said plateswhich is greater than the thickness of the door and is adapted toaccommodate the case of the operating unit, one of said plates having awall extending perpendicularly therefrom and adapted to extend into anopening in said door to prevent movement of the housing relativelythereto, the other of said plates having a wall portion telescoping witha portion of the wall on the first-mentioned plate, the said telescopingwall portions enclosing the lock case, "means for securing said lockcase within said housing and clamping the plates to the opposite sidesof the door, and separate means for securing the latch unit within saidhousing and clamping the outer ends of said plates to theopp'os'itesides of the door.

14. For a cylindrical door lock includih'g an operating unit and a latchunit, said operating unit including a case having an inner and an outersleeve extending co-axially from opposite ends thereof; an adapterhousing for mounting said door lock on a door, the said housingincluding an inner and an outer plate, the outer plate having an openingtherein for receiving the outer sleeve, means securing said outer sleeveto the outer plate, a wall extending perpendicularly from the inner faceof the outer plate, the said inner plate having an opening extendingtherethrough and a wall to receive the said case surrounding saidopening and telescoping with the wall of the outer plate, an escutcheonplate covering the opening in the inner plate and having an openingtherein coaxial with the opening in the outer plate, means threaded tothe inner sleeve for securing the said escutcheon plate against theinner plate and drawing said inner and outer plates together intoclamping position against the opposite faces of the door, and separatemeans for securing the latch unit within said housing in operativeposition relatively to an operating mechanism within the lock case.

15. The subject matter set forth in claim 14 including projectionsextending from the face of the inner plate adjacent the opening thereinand engaging the case for preventing rotation thereof within thehousing.

16. For a cylindrical door lock including an operating unit and a latchunit, the said operating unit including a cylindrical case having aninner and an outer sleeve extending co-axially from opposite endsthereof; an adapter housing for mounting said door lock on a door thatis thinner than the case, said adapter housing including an inner and anouter plate each of which contains a recess in its face providing aspace between said plates which is greater than the thickness of thedoor and is adapted to accommodate the said case, means cooperating withsaid sleeves for clamping the plates to the opposite sides of the doorand thereby securing the housing to the door and the said case withinthe housing, and a projection on at least one of said plates inengagement with said case for preventing rotation thereof within thehousing.

17. For a cylindrical door lock including an operating unit and a latchunit having a face plate, said operating unit having a case with aninner and an outer sleeve extending co-axially from the opposite sidesthereof; an adapter housing for mounting said door lock on a door, saidadapter housing including an inner and an outer plate having co-axialopenings therein to receive said sleeves, means cooperating with saidsleeves for clamping said plates against opposite sides of the door withthe lock case contained therebetween, one of said plates having aperpendicular frame extending therefrom toward the other plate andsliclably fitting within a notch in said other plate to permitadjustment between said plates for accommodating variations in thethickness of doors between the plates, the said frame having an openingtherein to receive the face plate of said latch unit, and means forsecuring said face plate in said frame and clamping the, inner and outerplates to the opposite sides of the door.

18. The subject matter set forth in claim 17 wherein the securing meansfor the face plate include bosses projecting from the opposed faces ofthe inner and outer plates and having cam surfaces thereon, a clampingbar having cam surfaces cooperating with the cam surfaces on said bossesfor drawing the inner and outer plates toward each other for clampingthem against the opposite sides of. the door, and screws extendingthrough the face plate and threaded to said clamping bar for drawing itinto clamping position and securing the face plate to the perpendicularextension.

19. The subject matter set forth in claim 17 wherein the secondmentioned clamping means includes two pairs of bosses extending towardeach other from the inner and outer plates and located at opposite sidesof the latch unit, each of said bosses having a cam surface thereon, aclamping bar between each pair of said bosses having surfacescooperating with the cam surfaces on the bosses for drawing theplates'into clamped position, and screw members extending through theface plate at opposite sides of the latch unit and each threaded to oneof said bars for drawing them into clamping position.

20. The subject matter set forth in claim 17 including pin membersextending across the opening in said frame and providing an abutment forthe face plate of the latch unit.

References Cited in the file of this patent UNITED STATES PATENTS YoungMay 7, 1912 Wread July 9, 1929 Erath May 14, 1940 Gold et a1. Nov. 25,1941 Clark Sept. 18, 1951 Oxhandler et a1. Feb. 1, 1955

